Device to facilitate the drilling of holes centrally in staffs for watches



(No Model.)

W. M. PRESTON.

DEVICE TO FAGILITATE THE DRILLING OF HOLES GIEINTRALLY IN STAFFS FORWATCHES, Gas. No. 437,796. Patented Oct. 7, 1890.

UNITED STATES PATENT OFFICE.

IVILLIAIWI M. PRESTON, OF RONDOUT, NEIV YORK.

DEVICE TO FACILITATE THE DRILLING OF HOLES CENTRALLY IN STAFFS FORWATCHES, 8L0.

SPECIFICATION forming part of Letters Patent No. 437,796, dated October'7, 1890.

Application filed April 8, 1890- Serial No. 347,038. (No model.)

To aZZ whom it may concern.-

Be it known that I, WILLIAM M. PRESTON, a citizen of the United States,residing at Rondout,in the county of Ulster and State of New York, haveinvented certain new and useful Improvements in a Device to Facilitatethe Drilling of Holes Centrally in Staffs for Watch-Pinions, the, and Ido hereby declare the following to be a full, clear, and exactdescription of the invention, such as Will enable others skilled in theart to which it appertains to make and use the same.

My invention relates to a device to be operated by hand or in connectionwith the sliding rest of a lathe for the purpose of drilling holes inthe end of the staff or pinion of a watch-wheel, and its object is tofacilitate the drilling of said holes correctly and prevent the drillfrom breaking and the staff from splitting. I obtain said object by acertain arrangement and construction, fully described in thisspecification, and illustrated in the accompanying drawings, in WhichFigures 1, 2, and 3 are views completely illustrating said device.

A designates the device, which comprises the handle a, the portion a,and the perforated rotating disk a Said disk is pivoted to the portiona, and it is constructed with the orifices a These orifices or openingsare cone-shaped and of different sizes, corresponding in number and sizeto the difierent pinions or staffs upon which it is designed to be used.

The usual mode in which jewelers pivot a staff or pinion. of awatchovheel consists in finding the center of same and then drilling thehole is said center by means of a drill while the staif is beingrevolved with a lathe. Frequently they accomplish this without the useof the lathe. It will readily be observed that this is a very tediousand difficult undertaking. Besides in doing this the staff or pinionWill frequently split, the drill will get broken, and the orifice,instead of being perpendicular, is frequently the reverse, render ingthe work useless. By the aid of my invention I propose to obviate all ofsaid difficulties and to perform the work perfectly and in one-fifth ofthe time required by the old method.

By placing the staff or pinion to be pivoted in the conical openings oof the disk andinsorting the drill in said openings you have at once thecenter of the staff or pinion without the trouble of finding same. Thestaff or pinion is then caused to rotate within said conical openings bymeans of a lathe or any other force, and the Work is correctly andquickly performed.

Having fully described my invention and its advantages, What I claim,and desire to secure by Letters Patent, is

1. In a device to facilitate the drilling of holes centrally in staflsfor watch-pinions, &c., the rotating disk or plate with graduatedconical perforations, in combination with any suitable handle foroperating the same by hand or in connectionwith the sliding rest of alathe, substantially as described and set forth.

2. In a device to facilitate the drilling of holes centrally in staifsfor watch-pinions, &c., the rotating disk. a pivoted to the stem orportion a, of the handle a, substantially as described.

3. The combination of the handle a, the stem at of said handle, and thedisk a substantially as described, and for the purpose set forth.

In testimony whereof I affix my signature in presence of two witnesses.

\VILLIAM M. PRESTON.

Witnesses:

EMANUEL Mnrzonn, WILLIAM LAWTON.

